Belzutifan

Belzutifan, sold under the brand name Welireg, is an anti-cancer medication used for the treatment of von Hippel–Lindau disease-associated renal cell carcinoma. It is taken by mouth. Belzutifan is an hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor.

Belzutifan's capacity to reduce serum erythropoietin verified its clinical applicability for the treatment of malignancies linked to von Hippel-Lindau (VHL), such as renal cell carcinoma (RCC) with clear cell histology (ccRCC), pancreatic lesions, neuroendocrine tumors, and CNS hemangioblastomas or pancreatic neuroendocrine tumors (pNET), which do not require immediate surgery. Belzutifan obtained a disease control rate of 80% in pretreated ccRCC during a phase I trial.

The most common side effects include decreased hemoglobin, anemia, hypoxia, fatigue, increased creatinine, headache, dizziness, increased glucose, and nausea.

Belzutifan was approved for medical use in the United States in August 2021, in the United Kingdom in May 2022, and in the European Union in February 2025. Belzutifan is the first hypoxia-inducible factor-2 alpha inhibitor therapy approved in the US. The US Food and Drug Administration (FDA) considers it to be a first-in-class medication. Belzutifan is the first medication to be awarded an "innovation passport" from the UK Medicines and Healthcare products Regulatory Agency.